Easton's Bible Dictionary (1897)
In Num. 6:4 (Heb. zag) it means the “skin” of a grape. In 2 Kings 4:42 (Heb. tsiqlon) it means a “sack” for grain, as rendered in the Revised Version. In Luke 15:16, in the parable of the Prodigal Son, it designates the beans of the carob tree, or Ceratonia siliqua. ” This tree is in “February covered with innumerable purple-red pendent blossoms, which ripen in April and May into large crops of pods from 6 to 10 inches long, flat, brown, narrow, and bent like a horn (whence the Greek name keratia, meaning ‘little horns’), with a sweetish taste when still unripe.
” The bean is called a “gerah,” which is used as the name of the smallest Hebrew weight, twenty of these making a shekel.